Update Solr 10 major changes page

[ilariapet]

Update the Solr 10 major changes page to include new vector search features, new LTR cache and hybrid search component.

[gus-asf]

10.0 is already released, are these 10.1 changes?

[ilariapet]

10.0 is already released, are these 10.1 changes?

Yes, I’m aware that 10.0 has already been released. However, I noticed that some changes related to 10.0 were missing from that page, so I added them :(
Should I have handled it differently?

[gus-asf]

Typically this list of features is drawn from a set of suggestions given to the release manager at release time. There is often discussion of what to include, since this section is highlights, not a list of all changes. There isn't any reason that we can't amend the list with discussion on the list, though it is a tad unusual to do so this long after. A PR like this is fine for starting a discussion.